The effect of marital status on the survival of patients with multiple myeloma

Figures & data

Table 1. Demographic and clinical characteristics of multiple myeloma patients according to marital status.

Characteristic	Total N (%)	Married N (%)	Unmarried N (%)	Divorced/separated N (%)	Single N (%)	Widowed N (%)	P value
All patients	48,952 (100)	29,607 (60.5)	19,345 (39.5)	5,147 (10.5)	6,851 (14.0)	7,347 (15.0)
Age at diagnosis (years)							<0.001
<45	1,538 (3.1)	900 (3.0)	638 (3.3)	119 (2.3)	510 (7.4)	9 (0.1)
45–54	5,439 (11.1)	3,287 (11.1)	2,152 (11.1)	693 (13.5)	1,357 (19.8)	102 (1.4)
55–64	11,444 (23.4)	7,343 (24.8)	4,101 (21.2)	1,542 (30.0)	2,082 (30.4)	477 (6.5)
65–74	14,731 (30.1)	9,570 (32.3)	5,161 (26.7)	1,736 (33.7)	1,684 (24.6)	1,741 (23.7)
≥75	15,800 (32.3)	8,507 (28.7)	7,293 (37.7)	1,057 (20.5)	1,218 (17.8)	5,018 (68.3)
Sex							<0.001
Male	27,411 (56.0)	19,287 (65.1)	8,124 (42.0)	2,419 (47.0)	3,708 (54.1)	1,997 (27.2)
Female	21,541 (44.0)	10,320 (34.9)	11,221 (58.0)	2,728 (53.0)	3,143 (45.9)	5,350 (72.8)
Period of diagnosis							<0.001
2007–2011	22,242 (45.4)	13,462 (45.5)	8,780 (45.4)	2,342 (45.5)	2,876 (42.0)	3,562 (48.5)
2012–2016	26,710 (54.6)	16,145 (54.5)	10,565 (54.6)	2,805 (54.5)	3,975 (58.0)	3,785 (51.5)
Race							<0.001
White	30,867 (63.1)	20,115 (67.9)	10,752 (55.6)	2,856 (55.5)	3,160 (46.1)	4,736 (64.5)
Black	9,893 (20.2)	4,341 (14.7)	5,552 (28.7)	15,44 (30.0)	2,453 (35.8)	1,555 (21.2)
Hispanic	5,476 (11.2)	3,256 (11.0)	2,220 (11.5)	588 (11.4)	979 (14.3)	653 (8.9)
Asian	2,716 (5.5)	1,895 (6.4)	821 (4.2)	159 (3.1)	259 (3.8)	403 (5.5)
Insurance status							<0.001
Insured	42,191 (86.2)	26,998 (91.2)	15,193 (78.5)	4,064 (79.0)	4,745 (69.3)	6,384 (86.9)
Medicaid	5,613 (11.5)	2,084 (7.0)	3,529 (18.2)	937 (18.2)	1,716 (25.0)	876 (11.9)
Uninsured	1,148 (2.3)	525 (1.8)	623 (3.2)	146 (2.8)	390 (5.7)	87 (1.2)
Median household income ($)							<0.001
Quartile 1 (>72,590)	12,030 (24.6)	7,563 (25.5)	4,467 (23.1)	1,119 (21.7)	1,618 (23.6)	1,730 (23.5)
Quartile 2 (57,971–72,590)	11,916 (24.3)	7,345 (24.8)	4,571 (23.6)	1,319 (25.6)	1,524 (22.2)	1,728 (23.5)
Quartile 3 (50,351–57,970)	12,828 (26.2)	7,650 (25.8)	5,178 (26.8)	1,391 (27.0)	1,946 (28.4)	1,841 (25.1)
Quartile 4 (<50,350)	12,178 (24.9)	7,049 (23.8)	5,129 (26.5)	1,318 (25.6)	1,763 (25.7)	2,048 (27.9)
Education (% At least Bachelor’s degree)							<0.001
Quartile 1 (>38.45)	11,777 (24.1)	7,176 (24.2)	4,601 (23.8)	1,213 (23.6)	1,708 (24.9)	1,680 (22.9)
Quartile 2 (30.77–38.45)	12,136 (24.8)	7,456 (25.2)	4,680 (24.2)	1,310 (25.5)	1,641 (24.0)	1,729 (23.5)
Quartile 3 (22.35–30.76)	12,456 (25.4)	7,441 (25.1)	5,015 (25.9)	1,306 (25.4)	1,830 (26.7)	1,879 (25.6)
Quartile 4 (<22.35)	12,583 (25.7)	7,534 (25.4)	5,049 (26.1)	1,318 (25.6)	1,672 (24.4)	2,059 (28.0)
Chemotherapy							<0.001
Yes	31,008 (63.3)	19,586 (66.2)	11,422 (59.0)	3,367 (65.4)	4,397 (64.2)	3,658 (49.8)
No/Unknown	17944 (36.7)	10,021 (33.8)	7,923 (41.0)	1,780 (34.6)	2,454 (35.8)	3,689 (50.2)

Abbreviations: N, number.

Figure 1. Survival curves for patients with multiple myeloma according to marital status. (a) Overall survival; (b) cancer-specific survival; (c) Overall survival after propensity score matching (PSM); and (d) cancer-specific survival after PSM.

Table 2. Univariate and multivariate analyses of overall survival in multiple myeloma patients.

Variable	Univariate		Multivariate
	HR (95% CI)	P value	HR (95% CI)	P value
Age at diagnosis (years)		<0.001		<0.001
<45	Reference		Reference
45–54	1.376 (1.235–1.532)	<0.001	1.425 (1.279–1.587)	<0.001
55–64	1.703 (1.538–1.886)	<0.001	1.804 (1.628–1.998)	<0.001
65–74	2.395 (2.166–2.647)	<0.001	2.566 (2.319–2.840)	<0.001
≥75	4.619 (4.182–5.102)	<0.001	4.747 (4.290–5.253)	<0.001
Sex		<0.001		<0.001
Male	Reference		Reference
Female	0.934 (0.911–0.958)	<0.001	0.834 (0.812–0.857)	<0.001
Period of diagnosis		<0.001		<0.001
2007–2011	Reference	<0.001	Reference	<0.001
2012–2016	0.881 (0.857–0.906)	<0.001	0.876 (0.852–0.901)	<0.001
Marital status		<0.001		<0.001
Married	Reference		Reference
Divorced/separated	1.117 (1.071–1.165)	<0.001	1.214 (1.163–1.268)	<0.001
Single	1.144 (1.102–1.189)	<0.001	1.332 (1.280–1.386)	<0.001
Widowed	1.885 (1.824–1.948)	<0.001	1.364 (1.315–1.414)	<0.001
Race		<0.001		0.008
White	Reference		Reference
Black	0.912 (0.883–0.942)	<0.001	0.947 (0.915–0.980)	0.002
Hispanic	0.928 (0.890–0.967)	<0.001	0.969 (0.928–1.012)	0.154
Asian	0.889 (0.838–0.942)	<0.001	0.950 (0.896–1.009)	0.094
Insurance status
Insured	Reference	<0.001	Reference	<0.001
Medicaid	1.258 (1.211–1.307)	<0.001	1.381 (1.326–1.438)	<0.001
Uninsured	0.850 (0.779–0.928)	<0.001	1.224 (1.119–1.338)	<0.001
Median household income ($)		<0.001		<0.001
Quartile 1 (>72,590)	Reference		Reference
Quartile 2 (57,971–72,590)	1.013 (0.976–1.051)	0.491	0.992 (0.951–1.035)	0.724
Quartile 3 (50,351–57,970)	1.177 (1.136–1.220)	<0.001	1.093 (1.040–1.148)	<0.001
Quartile 4 (<50,350)	1.245 (1.201–1.290)	<0.001	1.092 (1.034–1.153)	0.002
Education (% At least Bachelor’s degree)		<0.001		<0.001
Quartile 1 (>38.45)	Reference		Reference
Quartile 2 (30.77–38.45)	1.085 (1.046–1.126)	<0.001	1.069 (1.026–1.114)	0.002
Quartile 3 (22.35–30.76)	1.169 (1.127–1.212)	<0.001	1.085 (1.034–1.138)	0.001
Quartile 4 (<22.35)	1.305 (1.259–1.352)	<0.001	1.193 (1.131–1.260)	<0.001
Chemotherapy		<0.001		<0.001
Yes	Reference		Reference
No/Unknown	1.300 (1.267–1.334)	<0.001	1.072 (1.044–1.101)	<0.001

Abbreviations: HR, hazard ratio; CI, confidence interval.

Table 3. Univariate and multivariate analyses of multiple myeloma cancer-specific survival.

Variable	Univariate		Multivariate
	HR (95% CI)	P value	HR (95% CI)	P value
Age at diagnosis (years)		<0.001		<0.001
<45	Reference		Reference
45–54	1.256 (1.110–1.421)	<0.001	1.301 (1.150–1.473)	<0.001
55–64	1.476 (1.313–1.658)	<0.001	1.574 (1.400–1.769)	<0.001
65–74	1.736 (1.547–1.949)	<0.001	1.884 (1.676–2.117)	<0.001
≥75	2.918 (2.603–3.272)	<0.001	3.049 (2.713–3.426)	<0.001
Sex
Male	Reference		Reference
Female	1.034 (1.000–1.069)	0.052	0.942 (0.909–0.976)	0.001
Year		<0.001		<0.001
2007–2011	Reference	<0.001	Reference	<0.001
2012–2016	0.844 (0.814–0.876)	<0.001	0.841 (0.811–0.873)	<0.001
Marital status		<0.001		<0.001
Married	Reference		Reference
Divorced/separated	1.128 (1.067–1.193)	<0.001	1.172 (1.107–1.241)	<0.001
Single	1.201 (1.144–1.262)	<0.001	1.312 (1.246–1.382)	<0.001
Widowed	1.742 (1.666–1.821)	<0.001	1.333 (1.269–1.401)	<0.001
Race		<0.001		<0.001
White	Reference		Reference
Black	0.901 (0.863–0.942)	<0.001	0.887(0.847–0.929)	<0.001
Hispanic	1.030 (0.976–1.086)	0.281	1.021 (0.966–1.079)	0.468
Asian	0.989 (0.918–1.065)	0.765	1.039 (0.963–1.121)	0.322
Insurance status
Insured	Reference	<0.001	Reference	<0.001
Medicaid	1.360 (1.294–1.428)	<0.001	1.402 (1.330–1.478)	<0.001
Uninsured	1.008 (0.905–1.123)	0.882	1.260 (1.128–1.406)	<0.001
Median household income ($)		<0.001		<0.001
Quartile 1 (>72,590)	Reference		Reference
Quartile 2 (57,971–72,590)	1.039 (0.989–1.091)	0.132	1.012 (0.957–1.071)	0.675
Quartile 3 (50,351–57,970)	1.235 (1.178–1.295)	<0.001	1.166 (1.093–1.245)	<0.001
Quartile 4 (<50,350)	1.265 (1.206–1.326)	<0.001	1.139 (1.059–1.224)	<0.001
Education (% At least Bachelor’s degree)		<0.001		<0.001
Quartile 1 (>38.45)	Reference		Reference
Quartile 2 (30.77–38.45)	1.153 (1.097–1.211)	<0.001	1.124 (1.064–1.188)	<0.001
Quartile 3 (22.35–30.76)	1.197 (1.140–1.257)	<0.001	1.067(1.000–1.138)	0.049
Quartile 4 (<22.35)	1.351 (1.288–1.417)	<0.001	1.195 (1.112–1.284)	<0.001
Chemotherapy		0.429
Yes	Reference
No/Unknown	1.014(0.979–1.051)	0.429

Abbreviations: HR, hazard ratio; CI, confidence interval.

Table 4. Baseline characteristics of multiple myeloma patients according to marital status after PSM.

Characteristic	Total N (%)	Married N (%)	Unmarried N (%)	P value
All patients	27,928 (100)	13,964 (50.0)	13,964 (50.0)
Age at diagnosis (years)				1.000
<45	658 (2.4)	328 (2.3)	330 (2.4)
45–54	2,920 (10.5)	1,461 (10.5)	1,459 (10.4)
55–64	6,353 (22.7)	3,177 (22.8)	3,176 (22.7)
65–74	8,511 (30.5)	4,252 (30.4)	4,259 (30.5)
≥75	9,486 (34.0)	4,746 (34.0)	4,740 (33.9)
Sex				0.914
Male	14,049 (50.3)	7,029 (50.3)	7,020 (50.3)
Female	13,879 (49.7)	6,935 (49.7)	6,944 (49.7)
Period of diagnosis				0.895
2007–2011	12,445 (44.6)	6,228 (44.6)	6,217 (44.5)
2012–2016	15,483 (55.4)	7,736 (55.4)	7,747 (55.5)
Race				0.998
White	17,604 (63.0)	8,804 (63.0)	8,800 (63.0)
Black	6,053 (21.7)	3,027 (21.7)	3,026 (21.7)
Hispanic	3,088 (11.1)	1,545 (11.1)	1,543 (11.0)
Asian	1,183 (4.2)	588 (4.2)	595 (4.3)
Insurance status				0.863
Insured	24,757 (88.6)	12,380 (88.7)	12,377 (88.6)
Medicaid	2,743 (9.8)	1,365 (9.8)	1,378 (9.9)
Uninsured	428 (1.5)	219 (1.6)	209 (1.5)
Median household income ($)				0.994
Quartile 1 (>72,590)	6,780 (24.3)	3,393 (24.3)	3,387 (24.3)
Quartile 2 (57,971–72,590)	6,673 (23.9)	3,339 (23.9)	3,334 (23.9)
Quartile 3 (50,351–57,970)	7,531 (27.0)	3,755 (26.9)	3,776 (27.0)
Quartile 4 (<50,350)	6,944 (24.9)	3,477 (24.9)	3,467 (24.8)
Education (% At least Bachelor’s degree)				0.997
Quartile 1 (>38.45)	6,675 (23.9)	3,339 (23.9)	3,336 (23.9)
Quartile 2 (30.77–38.45)	6,827 (24.4)	3,420 (24.5)	3,407 (24.4)
Quartile 3 (22.35–30.76)	7,165 (25.7)	3,576 (25.6)	3,589 (25.7)
Quartile 4 (<22.35)	7,261 (26.0)	3,629 (26.0)	3,632 (26.0)
Chemotherapy				0.941
Yes	17,558 (62.9)	8,776 (62.8)	8,782 (62.9)
No/Unknown	10,370 (37.1)	5,188 (37.2)	5,182 (37.1)

Abbreviations: PSM, propensity score matching; N, number.

Table 5. Univariate analysis of overall survival (OS) and cancer-specific survival (CSS) for patients with multiple myeloma after propensity score matching (PSM).

Variable	OS		CSS
	HR (95% CI)	P value	HR (95% CI)	P value
Marital status		<0.001		<0.001
Married	Reference		Reference
Unmarried	1.242(1.201–1.283)	<0.001	1.209 (1.157–1.263)	<0.001

Figure 2. Overall survival (OS) and cancer-specific survival (CSS) in patients with multiple myeloma by age at diagnosis, sex, and income. (a) Age at diagnosis and marital status, OS; (b) age at diagnosis and marital status, CSS; (c) sex and marital status, OS; (d) sex and marital status, CSS; (e) income and marital status, OS; and (f) income and marital status, CSS.

Figure 3. Overall survival (OS) and cancer-specific survival (CSS) in patients with multiple myeloma by race and period of diagnosis. (a) Race and marital status, OS; (b) race and marital status, CSS; (c) period of diagnosis and marital status, OS; and (d) period of diagnosis and marital status, CSS.

Table 6. Multivariate adjusted HRs for overall survival (OS) and multiple myeloma cancer-specific survival (CSS) associated with marital status (unmarried vs married) stratified by age at diagnosis, sex, socio-economic status (SES), race, and period of diagnosis.

Variable	OS		CSS
	HR (95% CI)	P value	HR (95% CI)	P value
All	1.313 (1.277–1.349)	<0.001	1.286 (1.240–1.333)	<0.001
Age at diagnosis (years)
<65	1.329 (1.262–1.399)	<0.001	1.253 (1.178–1.334)	<0.001
65–74	1.298 (1.234–1.366)	<0.001	1.239 (1.159–1.324)	<0.001
≥75	1.265 (1.214–1.318)	<0.001	1.227 (1.156–1.301)	<0.001
Sex
Male	1.351 (1.303–1.400)	<0.001	1.335 (1.270–1.404)	<0.001
Female	1.251 (1.201–1.302)	<0.001	1.195 (1.133–1.259)	<0.001
SES
Higher SES (Quartile 1–2)	1.372 (1.318–1.428)	<0.001	1.353 (1.283–1.427)	<0.001
Lower SES (Quartile 3–4)	1.249 (1.204–1.296)	<0.001	1.211 (1.155–1.271)	<0.001
Race
White	1.338 (1.294–1.384)	<0.001	1.308 (1.251–1.369)	<0.001
Black	1.288 (1.210–1.371)	<0.001	1.288 (1.187–1.398)	<0.001
Hispanic	1.221 (1.125–1.326)	<0.001	1.134 (1.024–1.255)	0.015
Asian	1.253 (1.105–1.420)	<0.001	1.197 (1.026–1.397)	0.022
Period of diagnosis
2007–2011	1.276 (1.233–1.320)	<0.001	1.261 (1.205–1.320)	<0.001
2012–2016	1.377 (1.317–1.439)	<0.001	1.320 (1.246–1.398)	<0.001